Commuters will be tracked through their mobile phones as they navigate the London Underground network in a four-week trial that began today.

By using signals sent from mobiles to the network’s free wi-fi, Transport for London (TfL) hopes to better understand how people move through stations, interchange between services and how crowding develops.

Data from phones carried by people travelling through 54 stations within Zones 1 to 4 will be used in the trial.

TfL’s chief technology officer Shashi Verma, said: “This short trial will help us understand whether wi-fi connection data could help us plan and operate our transport network more effectively for customers.”

Currently TfL can only tell where people enter and exit tube stations, but not the routes they take or the interchanges they make.

“Historically, if we wanted to know how people travelled we would have to rely on paper surveys and manual counting, which is expensive, time-consuming and limited in detail and reliability,” continued Ms Verma.

“We hope the results of this trial will enable us to provide customers with even better information for journey planning and avoiding congestion.”

A spokesman added no information which can identify commuters or their browsing history data will be collected.

Some of the 54 stations included in the trial include Aldgate, Chancery Lane, Charing Cross, Holborn, Liverpool Street, Moorgate, Monument, Tower Hill and London Bridge.

People wanting to opt out of the trial can either turn off wi-fi on their device or switch it to airplane mode, while travelling in any of the stations.

For more information about the trial, visit tfl.gov.uk/privacy.